Good deal on organic twin mattress, maybe a naturepedic?

inlove5

  iI, we are purchasing a twin mattress for our 3 1/2 year old for Christmas and want to get something organic.  Our older son has a naturepedic and that has been a good fit for him (though it is so very firm that we lay a fleece blanket over top to make it a bit cozier and later on I'm sure we can get a nice topper).
   The naturepedic seems to be the best priced and right now that is a concern but we are open to other ideas if they aren't too far off the budget.  His infant mattress is organic latex so if I found an afforable organic latex that would be cool.  Do you know any sites that have sales, coupons, or discounts available on the Naturepedic or another organic mattress that you reccomend?  The best price I have seen is $649 with free shipping for their base model- the one sided quilted twin.  Any suggestions?  Thank you for your help : )
  Also I desperately need to find a hulk backpack for that same 3 1/2 year old but I dont want ANY lead, pthalates, etc- (other than just complying with the maximum allowable I want NO bad stuff- well as best as can be done).  Maybe a backpack and lunch box that I can get the Incredible Hulk embroidered on?  So far no one is able to embroider The Hulk becasue of copyright- ideas?  thanks again